According to UN Secretary-General Ban Ki-moon, over the past decade, the number of individuals living in urban areas who lack access to drinking water in their home or the immediate vicinity has increased by an estimated 114 million, while the number who lack access to basic sanitation facilities has risen by 134 million. An estimated 51 million people in the Democratic Republic of Congo have no access to safe drinking water, and between 30 and 60 percent of the urban population of sub-Saharan Africa has no access to the municipal water supply. In these and other regions worldwide where access to potable water and sanitation services are limited, individuals may employ alternative methods of purifying water, such as boiling, chemical disinfection, and filtration. While these methods offer an effective means of generating a supply of safe drinking water, the quality of water used in farming is also critical, as water-borne pathogens on crops can cause diseases such as typhoid and cholera.

Both governmental agencies and non-profit organizations have established initiatives aimed at increasing the availability of water, purifying existing water sources, and improving sanitation services worldwide. By ensuring that safe water is available for consumption and farming, and that sanitation services are sufficient, the transmission of water-borne illnesses can be mitigated. In addition, providing individuals in regions facing shortages of potable water with information about water purification options and treatments for cholera and other diarrheal illnesses can improve the healthcare infrastructure in these areas.

Cholera is an acute diarrheal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. Though three-quarters of individuals infected with V. cholerae do not exhibit any symptoms, they may shed the bacteria in their stool for seven to 14 days, potentially infecting others. While V. cholerae is the direct source of cholera infection, the deadly effects of the disease are caused by a toxin called CTX, that the bacteria produce in the small intestine of the host. CTX binds to the intestinal walls and interferes with the normal flow of sodium and chloride, causing the body to secrete large amounts of water and leading to diarrhea accompanied by dehydration. In individuals exhibiting the severe form of the disease, the rapid loss of fluids can lead to dehydration and shock, and without treatment death can occur within hours. Approximately one in 20 individuals infected with the bacteria develops symptoms associated with cholera, which include: severe, watery diarrhea; nausea and vomiting; muscle cramps; dehydration; and shock.

The rapid loss of fluids in a short period of time – often as much as a quart in an hour – associated with diarrhea due to cholera, makes the disease particularly deadly. In order to replenish the fluids and electrolytes that an individual with severe cholera has lost, Oral Rehydration Salts (ORS) must be administered. If a pre-formulated solution is not available, experts suggest combining one-half teaspoon salt, one-half teaspoon baking soda, and three tablespoons sugar in one liter of safe drinking water. With the prompt delivery of ORS, up to 80 percent of people can be treated successfully, with a fatality rate below one percent. Antibiotics may be used in conjunction with ORS to shorten the course and lessen the severity of the illness, however their delivery is less critical to cholera patients than rehydration. To help control the spread of the disease, two types of oral cholera vaccines are also available, but according to experts they provide only a short-term effect and should be administered in areas where ongoing water and sanitation improvement programs are in place.

HIV/AIDS and malaria are major health concerns worldwide, however the World Health Organization (WHO) reports across much of Asia and Africa secretory diarrhea – which accounts for 1.6 million deaths annually – is an even greater threat. Each day in India, diarrhea-related diseases kill 1,250 people, only slightly fewer than the H1N1 virus has killed globally to date (1,500), according to the WHO. Caused by E.coli, cholera, and other bacteria, viruses, or parasites, diarrhea affects individuals more often in areas that lack safe water and appropriate sanitation. In individuals with secretory diarrhea, infectious agents cause too much water to enter the bowel and be evacuated from the body, leading to excessive dehydration and eventually death if appropriate treatment is not received.

In nations of the developing world, including Bangladesh, India, Mali, and Pakistan, aid organizations and government agencies have begun distributing zinc supplements to villagers as a treatment for diarrhea. Data from recent studies documented in the August 2009 issue of the Journal of Leukocyte Biology suggest that zinc may help to activate the T-cells needed to destroy viruses and bacteria, including those that cause diarrhea. Time Magazine reports that in tablet or liquid form, zinc can be used in combination with oral-rehydration therapy (ORT). While it is not entirely clear how zinc helps halt diarrhea, Oliver Fontaine, a diarrhea specialist for the WHO, explains that a single course of zinc treatment can stave off diarrhea for three months.

Unlike zinc, which often produces an immediate improvement in an individual’s health, the glucose present in ORT (a solution of sugars and salts) slows the evacuation of fluids allowing for the absorption of electrolytes in the intestines, and halting the progression of dehydration to a chronic state. Because of the delay in the improvement of symptoms with ORT, “Mothers don’t see ORT as real treatment,” according to Eric Swedberg, senior director of health and nutrition at Save the Children U.S. Though ORT is an effective treatment for diarrhea, only about 35 percent of families in diarrhea-stricken countries utilize the method.

By offering zinc in combination with ORT, government-run programs in Ethiopia and Tanzania hope to increase the number of people surviving diarrheal outbreaks. Additionally, efforts are being made in Mali to add zinc to the country’s list of essential drugs, a step towards improving the distribution of the tablets. To halt the recent outbreaks of diarrhea in Nepal that have led to 235 deaths to date, the Office of the Prime Minister has begun coordinating efforts to construct a toilet in each household, provide sources of potable water, and improve waste disposal systems. In addition, the Nepali government has mobilized 298 personnel to aid in providing treatment in the area through 89 health camps.

To support these and other similar efforts, funding for the provision of the potentially life-saving drugs, and awareness of their effectiveness must be increased. In 2007, only four percent of all U.S. funding for research of epidemics in the developing world was devoted to finding solutions to decreasing the number of diarrhea-related deaths. Support from organizations like the Bill and Melinda Gates Foundation have provided some support, but additional funding is still needed not only to ensure that zinc tablets are more widely distributed, but also to assist in efforts to improve the quality of available water and waste treatment measures.